Glossary

Below are definitions of some of the technical terms found in the species webpages.

Abundance

The total number of individuals in a stock or a population.

Adipose fin

The fleshy appendage found on salmon and trout, located between the dorsal fin and the tail.

Anadromous

Species that move from saltwater to freshwater for spawning.

Appendage

The part of the body of an animal that sticks out from the central part of the body, for example a leg or a wing.

Barbel

A fleshy filament growing from the mouth or snout of a fish.

Benthic

An ecosystem found on the seafloor, including on the slope of the Continental Shelf.

Biomass

The total weight of a given species of fish in one area at a specific time. This can be for a full population or a defined portion of it.

Bivalve

Shellfish with two shells, including clams, cockles, mussels, oysters and scallops.

Breeding tubercles

Raised structures made of keratin typically shed after breeding.

Brood

Eggs carried externally on the underside of a female lobster.

Bycatch

The unintentional catch of a species when meaning to catch another. The retained portion of bycatch is called incidental catch, whereas the portion returned to the water is called discards.

Carapace

The protective bony shell covering the inner organs of any member of the crab or shrimp family. On a crab it is the top outer shell and must remain attached to prove that a crab in your possession is of legal size.

Caudal fin

Located at the posterior of the fish, the caudal fin moves, propels or pushes the fish through the water.

Concentric

Having the same center or axis.

Copepod

A class of crustacean zooplankton with numerous individuals, that are small (less than 8 millimetres) and form a large part of the diet of larval fish.

Clutch

A batch of eggs.

Dorsal

Referring or related to the back or upper side of an organism’s body.

Dredge

A fishing method whereby a dredge is dragged across the sea floor, either scraping or penetrating the sea floor.

Exoskeleton

A rigid external covering for the body providing both support and protection.

Extirpated

The local extinction of a species.

Finfish

Includes all fish other than crustaceans, echinoderms (sea urchins, sand dollars, etc.), molluscs, shellfish and marine mammals.

Forage species

A species that is below the top of an aquatic food chain. It’s an important source of food for at least some other aquatic species, and it experiences high mortality from these predators.

Gamete

A gamete is a reproductive cell of an animal or plant.

Gillnet

A fishing net that is hung vertically so that fish get trapped in it by their gills.

Larvae (Larval)

Transitional life form that develops from the spawned egg through various embryonic stages, with yolk as its only nutrient and energy supply, until it finally hatches into a free-living larva able to catch and digest prey organisms.

Lateral line

A visible line along the side of a fish consisting of sensory organs that detect pressure and vibration.

Median

A value at the midpoint of a series of observed values.

Mobile larvae

Juvenile form of an animal that is able to move independently.

Moult

Shedding an old shell to make way for new growth.

Nocturnal

Refers to the behavior of organisms that are active during the night.

Pelagic

Fish inhabiting the water column of the open ocean between the surface and the seafloor.

Phytoplankton

Very small plant like organisms that live in watery environments.

Plankton

Aquatic organisms, usually microscopic, that drift passively or, if they swim, are generally unable to move against the prevailing currents.

Potamodromous

Species that remain in freshwater for their entire life cycle, moving from lakes to rivers and tributary streams for spawning.

Production

The rate of generation of biomass in a stock.

Productivity

The rate at which biomass is generated in a stock.

Recruited (Recruitment)

When new fish are added to a population, commonly measured when small or young fish grow large or old enough to be caught in a fishery or scientific survey.

Roe

Edible eggs of fish.

Rostrum

A beak-like projection of the head extending from between the eyes.

Seine

A fishing net that hangs vertically in the water with floats at the top and weights at the bottom; the ends are drawn together to encircle the fish.

Self-seeding

Individuals that hatch and settle within the same area.

Semi-pelagic

Partially living its life in the water column.

Spawn

To release or deposit eggs.

Spawning stock biomass

The total weight of all fish in a stock that have reached reproductive maturity.

Striation

A long, thin line, mark, or strip of colour.

Substrate

The sediment, soil, bedrock and other material, either biotic or abiotic, that comprises the floor or bed of the sea, a lake, river or wetland.

Telson

The middle lobe of the tail of a crustacean or the terminal segment of the body of an arthropod.

Total Allowable Catch (TAC)

A catch limit set for a particular fishery.

Trap

Static fishing gear that work passively to entangle or trap fish that move towards or into it.

Trawl

A method of fishing that involves pulling a fishing net that is heavily weighted to keep it on the seafloor through the water behind 1 or more boats.

Trophic level

The position of an organism in a food web or chain, based on its nutritional relationship to the primary source of energy.

Water column

A vertical section of water from the surface to the bottom of the sea.

Weir

Permanent or semi-permanent structures that entrap fish, made from sticks, piles and netting, usually installed in tidal waters.

Year-class (Cohort)

Fish of a stock born in the same spawning year.

Zooplankton

Small but numerically abundant animals that are the basic source of food for juvenile stages of most marine organisms.